Prometheus Monitoring Interview Questions for DevOps [2025]

Prometheus Fundamentals

1. What is Prometheus, and how does it support DevOps monitoring?

Prometheus is an open-source time-series monitoring toolkit, ideal for DevOps due to its pull-based model and Kubernetes integration. A retail company monitored e-commerce APIs, ensuring real-time insights for rapid incident response.

Its scalability supports dynamic environments. PromQL enables flexible metric queries.

• Scrapes metrics via HTTP endpoints.
• Integrates with Grafana for visualization.
• Supports service discovery for Kubernetes.

Version configurations with Git for traceability.

2. Why is Prometheus a go-to tool for DevOps monitoring?

Prometheus excels in cloud-native monitoring with dynamic discovery and PromQL. A fintech firm used it to monitor microservices, ensuring high availability.

• Handles dynamic Kubernetes clusters.
• Queries metrics with PromQL for insights.
• Monitors with observability tools for reliability.

Its open-source nature reduces costs. Secure with RBAC for compliance.

3. How does Prometheus scrape metrics in DevOps pipelines?

Prometheus scrapes metrics from HTTP endpoints configured in prometheus.yml. A media company monitored streaming services, integrating with CI/CD for automated observability.

• Define scrape_configs in prometheus.yml.
• Use exporters like Node Exporter for metrics.
• Monitor scrape jobs with observability tools.

Secure endpoints with TLS. Version configs with Git.

4. When should DevOps teams use Prometheus?

Use Prometheus for dynamic, cloud-native environments like Kubernetes. A startup adopted it for microservices monitoring, leveraging its scalability.

• Ideal for containerized workloads.
• Supports real-time alerting.
• Integrates with Grafana for visualization.

Monitor performance with observability tools.

5. Where are Prometheus metrics stored in a DevOps setup?

Metrics are stored in a local TSDB. A logistics firm used TSDB for low-latency API metric queries, optimizing storage.

• Store data in /prometheus directory.
• Configure retention with --storage.tsdb.retention.time.
• Monitor storage with observability tools.

Version configs with Git for auditability.

6. Which components drive Prometheus monitoring?

A healthcare company monitored a patient portal using Prometheus components for robust observability.

• Prometheus Server: Scrapes and stores metrics.
• Alertmanager: Routes alerts.
• Exporters: Expose third-party metrics.
• PromQL: Queries time-series data.

These ensure comprehensive monitoring. Version with Git.

7. Who manages Prometheus in a DevOps team?

DevOps engineers and SREs manage Prometheus. A retail firm deployed it on Kubernetes for team collaboration.

• Deploy with Helm chart prometheus-operator.
• Configure RBAC for access control.
• Monitor with observability tools.

Secure with authentication.

8. What causes missing metrics in Prometheus?

Missing metrics result from failed scrapes or misconfigured targets. A telecom company fixed issues by validating prometheus.yml.

• Check scrape_configs for errors.
• Verify endpoints with curl.
• Monitor with observability tools.

Secure with TLS. Version with Git.

9. How do you debug Prometheus scrape issues in DevOps?

Debug by analyzing logs and targets. A financial firm fixed scrapes using GitOps to track configurations, ensuring traceability.

• Check logs with kubectl logs prometheus-pod.
• Validate scrape_configs in prometheus.yml.
• Monitor with observability tools.

Secure with RBAC. Version with Git.

10. Why does Prometheus use a pull-based model for DevOps?

The pull-based model ensures scalability in dynamic environments. A media company monitored APIs, reducing overhead compared to push-based systems.

• Scrapes endpoints via HTTP.
• Supports kubernetes_sd_configs for discovery.
• Monitors with observability tools.

Secure with authentication.

11. How do you ensure high availability in Prometheus?

Ensure HA with multiple instances and Thanos. A retail firm used replicated servers for e-commerce monitoring uptime.

• Deploy Thanos for global queries.
• Configure replicas in prometheus.yml.
• Monitor with observability tools.

Version with Git for auditability.

12. What are Prometheus exporters in DevOps?

Exporters expose third-party metrics for Prometheus. A healthcare firm used MySQL Exporter for database monitoring, ensuring compatibility.

• Examples: Node Exporter, Blackbox Exporter.
• Deploy as sidecar containers.
• Monitor with observability tools.

Secure with authentication.

13. When should DevOps teams use external labels?

Use external labels for federated setups to identify metrics. A telecom company labeled regional clusters for clarity.

• Define in prometheus.yml: external_labels.
• Use for multi-cluster monitoring.
• Monitor with observability tools.

Version with Git.

PromQL for DevOps

14. How do you query API latency with PromQL?

A startup monitored API latency with PromQL for performance. They used histogram_quantile(0.95, rate(http_request_duration_seconds_bucket[5m])) for 95th percentile latency.

• Use rate() for counter metrics.
• Filter with labels (e.g., {job="api"}).
• Visualize in Grafana dashboards.

Version queries with Git.

15. What causes empty PromQL query results?

Empty results stem from incorrect labels or time ranges. A logistics firm fixed a query by validating {env="prod"} and ranges.

• Check labels in Prometheus UI.
• Adjust time range (e.g., [5m]).
• Monitor with observability tools.

Secure with RBAC.

16. Why use subqueries in PromQL for DevOps?

Subqueries enable complex analysis for DevOps metrics. A media company calculated rolling averages for streaming metrics, improving insights.

• Syntax: sum(rate(metric[5m])[1h:5m]).
• Useful for trend analysis.
• Monitor with Grafana dashboards.

Secure with RBAC.

17. When should DevOps teams aggregate PromQL metrics?

Aggregate for summarized insights across services. A retail firm aggregated CPU usage with sum(rate(node_cpu_seconds_total[5m])).

Aggregation reduces noise in clusters. It aids system-wide analysis.

• Use sum() or avg() for aggregation.
• Filter by labels for specificity.
• Monitor with observability tools.

18. Where do you validate PromQL queries in DevOps?

Validate in Prometheus UI or Grafana. A financial firm tested queries with observability tools for accuracy.

• Use /query endpoint for testing.
• Visualize in Grafana for validation.
• Monitor with observability tools.

Version with Git.

19. Which PromQL functions are key for DevOps?

A startup used PromQL functions for microservices monitoring.

• rate(): Calculates per-second rates.
• histogram_quantile(): Computes percentiles.
• sum(): Aggregates metrics.

These enable detailed analysis. Monitor with observability tools.

20. Who writes PromQL queries in DevOps?

DevOps engineers write PromQL queries. A gaming company empowered teams to query latency for optimization.

• Write queries for performance insights.
• Share via Grafana dashboards.
• Monitor with observability tools.

Secure with RBAC.

21. How do you optimize PromQL queries for DevOps?

Optimize by reducing cardinality and time ranges. A telecom company improved query speed by filtering labels.

• Use specific labels (e.g., {job="api"}).
• Limit time ranges (e.g., [5m]).
• Monitor with observability tools.

Version with Git.

22. What is the role of labels in PromQL?

Labels enable filtering and grouping. A retail firm used {env="prod"} to isolate production metrics for analysis.

• Filter with {key="value"} syntax.
• Group with by() clause.
• Monitor with observability tools.

Secure with RBAC.

23. Why do PromQL queries fail in DevOps?

Failures result from syntax errors or high cardinality. A media company fixed a query by correcting syntax and label scope.

• Validate with promtool query check.
• Reduce cardinality with labels.
• Monitor with observability tools.

Version with Git.

24. How do you calculate error rates with PromQL?

Calculate error rates using rate() and sum(). A fintech firm queried rate(http_errors_total[5m]) / rate(http_requests_total[5m]) for reliability.

• Use rate() for counters.
• Divide for error rate.
• Visualize in Grafana.

Monitor with observability tools.

25. When should you use range vectors in PromQL?

Use range vectors for time-based analysis. A logistics company used [5m] for CPU trends, ensuring accuracy.

• Syntax: metric[5m] for ranges.
• Use with rate() or avg_over_time().
• Monitor with observability tools.

Version with Git.

26. Where do you store PromQL queries?

Store queries in Grafana or Git. A retail firm versioned queries in Git for collaboration.

• Save in Grafana dashboard JSON.
• Version in Git repositories.
• Monitor with observability tools.

Secure with RBAC.

27. Which PromQL query monitors CPU usage?

A healthcare company monitored CPU with PromQL, ensuring compliance with DevSecOps practices.

• Query: rate(node_cpu_seconds_total{mode="user"}[5m]).
• Filter by node labels.
• Visualize in Grafana.

Secure with RBAC. Monitor with observability tools.

Alerting for DevOps

28. How do you configure Prometheus alerts?

Configure alerts in prometheus.yml and route via Alertmanager. A media company set CPU alerts, notifying via Slack.

• Define rules in alert.rules.yml.
• Configure Alertmanager in prometheus.yml.
• Route to PagerDuty or email.

Monitor with observability tools. Version with Git.

29. What is Alertmanager’s role in DevOps?

Alertmanager handles routing, deduplication, and silencing. A logistics firm managed disk alerts, reducing noise.

• Deduplicates repeated alerts.
• Routes to Slack or PagerDuty.
• Silences during maintenance.

Version with Git for auditability.

30. Why do alerts fail to trigger?

Failures stem from misconfigured PromQL or Alertmanager. A startup fixed an alert by validating expressions.

• Check PromQL in rules files.
• Verify Alertmanager connectivity.
• Monitor with observability tools.

Secure with RBAC.

31. When should you silence alerts in DevOps?

Silence during maintenance or known issues. A retail company silenced alerts during a database upgrade.

• Use Alertmanager UI for silencing.
• Set duration and labels.
• Monitor with observability tools.

Version with Git.

32. Where do you define alerting rules?

Define in prometheus.yml or rules files. A banking firm set latency alerts in alert.rules.yml for rapid response.

• Use alert keyword in rules.
• Specify PromQL expressions.
• Monitor with observability tools.

Version with Git.

33. Which tools integrate with Alertmanager?

A financial firm integrated Alertmanager for incident response.

• Slack: Real-time notifications.
• PagerDuty: Escalation management.
• Email: Backup alerts.

These ensure timely responses. Monitor with observability tools.

34. Who manages Alertmanager in DevOps?

DevOps engineers manage Alertmanager. A telecom company configured routing for reliable alerts.

• Define routes in alertmanager.yml.
• Version with Git.
• Monitor with observability tools.

Secure with RBAC.

35. How do you troubleshoot missing alerts?

Troubleshoot by checking rules and logs. A media firm fixed missing alerts by correcting PromQL syntax.

• Validate with promtool check rules.
• Check logs with kubectl logs alertmanager.
• Monitor with observability tools.

Secure with access controls.

36. What causes high alert volumes?

High volumes result from low thresholds or noisy metrics. A retail firm optimized alerts with CI/CD metrics for stability.

• Adjust thresholds in rules.
• Filter noisy metrics with labels.
• Monitor with observability tools.

Version with Git.

37. Why use Alertmanager for DevOps?

Alertmanager ensures rapid incident response. A healthcare company routed alerts to PagerDuty for compliance.

• Configure routing in alertmanager.yml.
• Integrate with PagerDuty.
• Monitor with observability tools.

Version with Git.

38. How do you scale Alertmanager?

Scale with clustering and load balancing. A fintech firm used multiple instances for HA in a global cluster.

• Enable clustering in alertmanager.yml.
• Use HAProxy for load balancing.
• Monitor with observability tools.

Secure with RBAC. Version with Git.

39. What causes Alertmanager routing failures?

Failures stem from misconfigured routes or network issues. A startup fixed routing by validating alertmanager.yml.

• Check routes in alertmanager.yml.
• Verify network with kubectl describe pod.
• Monitor with observability tools.

Secure with authentication.

40. When should you use alert inhibition?

Use inhibition to suppress redundant alerts. A retail company inhibited low-priority alerts during incidents.

• Configure inhibition in alertmanager.yml.
• Define matchers for specificity.
• Monitor with observability tools.

Version with Git.

Kubernetes Monitoring

41. How does Prometheus monitor Kubernetes?

Prometheus monitors Kubernetes via service discovery. A financial firm tracked pods with kubernetes_sd_configs for scalability.

• Configure kubernetes_sd_configs in prometheus.yml.
• Use Node Exporter for cluster metrics.
• Monitor with observability tools.

Version with Git.

42. What is Kube-State-Metrics’ role?

Kube-State-Metrics exposes Kubernetes object states. A logistics firm monitored pod health for reliability.

• Deploy with Helm chart kube-state-metrics.
• Query kube_pod_status_phase.
• Monitor with observability tools.

Secure with RBAC.

43. Why use Prometheus Operator in DevOps?

The Operator automates monitoring setup. A media company deployed it for simplified scaling.

• Install with Helm chart prometheus-operator.
• Define ServiceMonitors for targets.
• Monitor with observability tools.

Version with Git.

44. When should you use service discovery?

Use for dynamic Kubernetes environments. A startup automated pod monitoring with kubernetes_sd_configs.

• Configure kubernetes_sd_configs for pods.
• Use Consul for external services.
• Monitor with observability tools.

Secure with RBAC.

45. Where do you configure Prometheus for Kubernetes?

Configure in prometheus.yml with kubernetes_sd_configs. A healthcare firm ensured compliance with DevSecOps practices.

• Define kubernetes_sd_configs in prometheus.yml.
• Specify roles like pod or service.
• Monitor with observability tools.

Version with Git.

46. Which exporters monitor Kubernetes?

A retail company used exporters for cluster monitoring.

• Node Exporter: System metrics.
• Kube-State-Metrics: Cluster state.
• Blackbox Exporter: Endpoint probing.

Monitor with observability tools. Version with Git.

47. Who deploys Prometheus in Kubernetes?

DevOps engineers deploy Prometheus. A telecom company used Helm for cluster monitoring.

• Deploy with Helm chart prometheus-operator.
• Configure RBAC for access.
• Monitor with observability tools.

Secure with authentication.

48. How do you monitor Kubernetes pods?

Monitor pods with service discovery and exporters. A financial firm tracked pod metrics with Kube-State-Metrics.

• Set kubernetes_sd_configs in prometheus.yml.
• Query kube_pod_status_phase.
• Monitor with observability tools.

Version with Git.

49. What causes missing Kubernetes metrics?

Missing metrics result from misconfigured discovery or RBAC. A startup fixed pod metrics by validating kubernetes_sd_configs.

• Check kubernetes_sd_configs in prometheus.yml.
• Verify RBAC with kubectl describe role.
• Monitor with observability tools.

Secure with authentication.

50. Why use Helm for Prometheus in Kubernetes?

Helm simplifies deployments with reusable charts. A media company deployed Prometheus Operator with Helm for automation.

• Install with helm install prometheus-operator.
• Customize with values.yaml.
• Monitor with observability tools.

Version with Git.

51. How do you troubleshoot service discovery?

Troubleshoot by validating kubernetes_sd_configs and logs. A retail firm fixed issues by checking pod annotations.

• Check kubernetes_sd_configs in prometheus.yml.
• Verify annotations with kubectl describe pod.
• Monitor with observability tools.

Secure with RBAC.

52. When should you use Blackbox Exporter?

Use for endpoint probing. A telecom company monitored API availability with HTTP probes.

• Configure probes in prometheus.yml.
• Query probe_success metrics.
• Monitor with observability tools.

Version with Git.

53. Where do you configure ServiceMonitors?

Configure in Prometheus Operator CRDs. A financial firm used ServiceMonitors for microservices monitoring.

• Define ServiceMonitors in manifests.
• Specify labels for target selection.
• Monitor with observability tools.

Version with Git.

54. Which Kubernetes metrics are critical?

A startup monitored Kubernetes with Prometheus, using Git branching for configs.

• kube_pod_status_phase: Pod health.
• node_cpu_seconds_total: CPU usage.
• kube_deployment_status_replicas: Deployment state.

Monitor with observability tools. Version with Git.

Troubleshooting Prometheus

55. How do you troubleshoot high CPU usage?

Troubleshoot by analyzing metrics and logs. A telecom company optimized CPU by adjusting scrape intervals.

• Query node_cpu_seconds_total with PromQL.
• Check logs with kubectl logs prometheus-pod.
• Monitor with observability tools.

Scale with Thanos.

56. What causes Prometheus memory issues?

Memory issues stem from high cardinality or large TSDB. A retail firm reduced usage by limiting labels.

• Query prometheus_tsdb_head_series for cardinality.
• Configure --storage.tsdb.max-block-duration.
• Monitor with observability tools.

Version with Git.

57. Why scale Prometheus in DevOps?

Scaling ensures performance in large clusters. A financial firm used Thanos for thousands of nodes.

• Use Thanos for distributed storage.
• Implement federation for multi-instance setups.
• Monitor with observability tools.

Version with Git.

58. When does Prometheus need federation?

Federation is needed for multi-cluster monitoring. A media company federated instances for global observability.

• Configure federation in prometheus.yml.
• Use /federate endpoint for aggregation.
• Monitor with observability tools.

Secure with authentication.

59. Where do you monitor Prometheus performance?

Monitor in Prometheus UI or Grafana. A logistics firm tracked scrape duration with Grafana.

• Query prometheus_engine_query_duration_seconds.
• Visualize in Grafana dashboards.
• Monitor with observability tools.

Version with Git.

60. Which metrics indicate Prometheus health?

A startup monitored Prometheus health for reliability.

• prometheus_target_interval_length_seconds: Scrape accuracy.
• prometheus_tsdb_head_series: Cardinality.
• process_resident_memory_bytes: Memory usage.

Monitor with observability tools. Version with Git.

61. Who troubleshoots Prometheus in DevOps?

DevOps engineers troubleshoot issues. A telecom company resolved scrape failures collaboratively.

• Check logs with kubectl logs.
• Validate with promtool check config.
• Monitor with observability tools.

Secure with RBAC.

62. How do you optimize scrape intervals?

Optimize by balancing frequency and load. A retail company set scrape_interval to 30s.

• Configure scrape_interval in prometheus.yml.
• Test with prometheus_target_interval_length_seconds.
• Monitor with observability tools.

Version with Git.

63. What causes slow Prometheus queries?

Slow queries result from high cardinality or large ranges. A media company optimized queries with feature flags to limit scope.

• Reduce labels for cardinality.
• Limit time ranges in PromQL.
• Monitor with observability tools.

Version with Git.

64. Why use Thanos for scaling?

Thanos enables long-term storage and federation. A financial firm used Thanos for global metric queries.

• Deploy Thanos sidecar with Prometheus.
• Use Thanos Querier for aggregation.
• Monitor with observability tools.

Version with Git.

65. How do you handle storage growth?

Handle growth with retention and compression. A startup reduced TSDB size with shorter retention.

• Set --storage.tsdb.retention.time=15d.
• Enable TSDB compression.
• Monitor with observability tools.

Version with Git.

66. What causes Prometheus to drop metrics?

Drops result from scrape timeouts or high cardinality. A telecom company fixed drops by increasing scrape_timeout.

• Adjust scrape_timeout in prometheus.yml.
• Monitor with prometheus_target_scrapes_dropped.
• Use observability tools.

Secure with authentication.

67. When should you use remote write?

Use remote write for long-term storage. A retail firm sent metrics to a remote TSDB for compliance.

• Configure remote_write in prometheus.yml.
• Use Thanos or VictoriaMetrics.
• Monitor with observability tools.

Version with Git.

Security in Monitoring

68. How do you secure Prometheus?

Secure with RBAC and reverse proxies. A banking firm used Nginx for authentication and RBAC for control.

• Configure RBAC with kubectl apply -f rbac.yaml.
• Use Nginx for secure endpoints.
• Monitor with observability tools.

Version with Git.

69. What causes sensitive metric exposure?

Exposure occurs from unsecured endpoints or RBAC issues. A healthcare company secured metrics with TLS.

• Use TLS for scrape endpoints.
• Restrict with kubectl create rolebinding.
• Monitor with observability tools.

Audit with Git.

70. Why secure Prometheus endpoints?

Securing endpoints prevents unauthorized access. A financial firm used TLS for GDPR compliance.

• Enable TLS in prometheus.yml.
• Use Nginx for authentication.
• Monitor with observability tools.

Version with Git.

71. When should you audit configurations?

Audit during compliance checks or incidents. A retail company audited prometheus.yml for GDPR.

Audits ensure compliance. They catch misconfigurations early.

• Use promtool check config.
• Track with Git.
• Monitor with observability tools.

72. Where do you store sensitive configs?

Store in secrets or Git. A telecom company used Kubernetes secrets with incident response tools for security.

• Create secrets with kubectl create secret generic.
• Version in Git.
• Monitor with observability tools.

Secure with RBAC.

73. Which tools enhance Prometheus security?

A startup used tools for compliance.

• Snyk: Scans vulnerabilities.
• Falco: Detects anomalies.
• Prometheus: Monitors security metrics.

These ensure robust security. Monitor with observability tools.

74. Who manages Prometheus security?

Security engineers manage Prometheus. A financial firm restricted access with RBAC.

• Apply RBAC with kubectl apply -f rbac.yaml.
• Scan with Snyk.
• Monitor with observability tools.

Version with Git.

75. How do you prevent unauthorized access?

Prevent with RBAC and authentication. A healthcare company restricted UI access to admins.

• Define RBAC with kubectl create role.
• Use Nginx for authentication.
• Monitor with observability tools.

Audit with Git.

76. What ensures Prometheus compliance?

Compliance is ensured with RBAC, audits, and encryption. A banking firm used TLS for regulations.

• Enable TLS for endpoints.
• Audit with promtool check config.
• Monitor with observability tools.

Version with Git.

77. Why use Alertmanager for compliance?

Alertmanager ensures timely incident response. A retail firm routed alerts to PagerDuty for audits.

• Configure routing in alertmanager.yml.
• Integrate with PagerDuty.
• Monitor with observability tools.

Version with Git.

Grafana for DevOps

78. How do you integrate Prometheus with Grafana?

Integrate for visualization. A startup created API metric dashboards for observability.

• Add Prometheus as a Grafana data source.
• Create dashboards with PromQL.
• Monitor with observability tools.

Version with Git.

79. What causes Grafana dashboard failures?

Failures stem from incorrect PromQL or data source issues. A media company fixed a dashboard by validating queries.

• Check PromQL in Grafana editor.
• Verify data source settings.
• Monitor with observability tools.

Version with Git.

80. Why use Grafana in DevOps?

Grafana visualizes metrics for insights. A retail firm monitored sales APIs with dashboards.

• Create dashboards with PromQL.
• Share for team collaboration.
• Monitor with observability tools.

Version with Git.

81. When should you create Grafana dashboards?

Create for critical metrics. A financial firm used dashboards for API latency with Kubernetes Operators.

• Define dashboards for key metrics.
• Use PromQL for queries.
• Monitor with observability tools.

Version with Git.

82. Where do you store Grafana configurations?

Store in Git or Grafana’s database. A telecom company versioned dashboards in Git.

• Export dashboards as JSON.
• Version in Git repositories.
• Monitor with observability tools.

Secure with RBAC.

83. Which Grafana features enhance monitoring?

A startup used Grafana features for monitoring.

• Dashboards: Visualize PromQL queries.
• Alerts: Trigger notifications.
• Annotations: Mark events.

These improve observability. Monitor with observability tools.

84. Who manages Grafana dashboards?

DevOps engineers manage dashboards. A media company shared dashboards for streaming metrics.

• Create in Grafana UI.
• Version JSON configs in Git.
• Monitor with observability tools.

Secure with RBAC.

85. How do you troubleshoot Grafana data source issues?

Troubleshoot by validating settings and connectivity. A retail firm fixed a Prometheus data source issue.

• Verify data source in Grafana settings.
• Test with curl.
• Monitor with observability tools.

Version with Git.

Advanced DevOps Monitoring

86. How do you monitor microservices?

Monitor with service discovery and exporters. A startup tracked API uptime with Blackbox Exporter.

• Configure kubernetes_sd_configs for services.
• Use Blackbox Exporter for probing.
• Monitor with observability tools.

Version with Git.

87. What causes high cardinality?

High cardinality results from excessive labels. A financial firm reduced cardinality by limiting label values.

• Query prometheus_tsdb_head_series.
• Limit labels in exporters.
• Monitor with observability tools.

Version with Git.

88. Why use service meshes with Prometheus?

Service meshes provide detailed metrics. A media company used Istio with Prometheus for traffic monitoring, leveraging service meshes.

• Install Istio with Helm.
• Query istio_request_count.
• Monitor with observability tools.

Version with Git.

89. When should you use remote read?

Use for querying external storage. A retail firm used remote read with Thanos for historical analysis.

• Configure remote_read in prometheus.yml.
• Use Thanos Querier.
• Monitor with observability tools.

Version with Git.

90. Where do you configure Prometheus for service meshes?

Configure in prometheus.yml with service discovery. A logistics firm monitored Istio with kubernetes_sd_configs, using feature flags for rollouts.

• Define kubernetes_sd_configs for Istio.
• Query istio_request_duration.
• Monitor with observability tools.

Version with Git.

91. Which metrics monitor microservices?

A startup monitored microservices for reliability.

• http_requests_total: Request volume.
• request_duration_seconds: Latency.
• error_rate: Error frequency.

Monitor with observability tools. Version with Git.

92. Who configures Prometheus for microservices?

DevOps engineers configure Prometheus. A telecom company set up API endpoint monitoring.

• Deploy Blackbox Exporter.
• Configure kubernetes_sd_configs.
• Monitor with observability tools.

Version with Git.

93. How do you monitor API performance?

Monitor with PromQL and exporters. A retail firm tracked latency with rate(http_request_duration_seconds_sum[5m]).

• Query latency with PromQL.
• Use Blackbox Exporter for uptime.
• Monitor with observability tools.

Version with Git.

94. What causes Prometheus overload?

Overload results from high scrape frequency or cardinality. A media company reduced load by increasing scrape_interval.

• Adjust scrape_interval in prometheus.yml.
• Monitor with prometheus_tsdb_head_series.
• Use observability tools.

Version with Git.

95. Why use Prometheus for observability?

Prometheus provides real-time monitoring. A financial firm used it for cluster observability.

• Query with PromQL.
• Integrate with Grafana.
• Monitor with observability tools.

Version with Git.

Performance Optimization

96. How do you optimize Prometheus?

Optimize by tuning scrape intervals and storage. A retail firm set scrape_interval to 30s for efficiency.

• Configure scrape_interval in prometheus.yml.
• Use TSDB compression.
• Monitor with observability tools.

Version with Git.

97. What causes slow Prometheus startups?

Slow startups result from large TSDB or WAL issues. A startup fixed startups by compacting TSDB.

• Set --storage.tsdb.retention.time=15d.
• Monitor with prometheus_tsdb_wal_corruptions_total.
• Use observability tools.

Version with Git.

98. Why does Prometheus consume excessive resources?

Excessive usage stems from high cardinality or scrapes. A telecom company set resource limits.

• Limit labels in exporters.
• Configure limits in deployment.yaml.
• Monitor with observability tools.

Version with Git.

99. When should you scale Prometheus?

Scale when metric volume exceeds capacity. A financial firm scaled with Thanos for thousands of metrics.

• Deploy Thanos sidecar.
• Use federation for multi-cluster setups.
• Monitor with observability tools.

Version with Git.

100. Where do you tune Prometheus performance?

Tune in prometheus.yml and manifests. A retail company optimized scrape_interval and limits.

• Adjust scrape_interval in prometheus.yml.
• Set limits in deployment.yaml.
• Monitor with observability tools.

Version with Git.

101. Which metrics optimize Prometheus?

A media company used metrics for optimization.

• prometheus_engine_query_duration_seconds: Query speed.
• prometheus_tsdb_head_series: Cardinality.
• process_cpu_seconds_total: CPU usage.

Monitor with observability tools. Version with Git.

102. Who optimizes Prometheus performance?

DevOps engineers optimize performance. A telecom company tuned scrape intervals for low latency.

• Adjust scrape_interval in prometheus.yml.
• Optimize TSDB with compression.
• Monitor with observability tools.

Version with Git.

103. How do you prepare for a Prometheus monitoring interview?

Prepare by practicing PromQL and Kubernetes integration. A candidate mastered Prometheus with monitoring tools in hands-on labs.

• Practice PromQL in Prometheus UI.
• Deploy with Helm chart prometheus-operator.
• Monitor with observability tools.

Version with Git.